Wilson D F
Biochim Biophys Acta. 1980 Dec 4;616(2):371-80. doi: 10.1016/0005-2744(80)90154-0.
The formalism called irreversible thermodynamics has been examined for its applicability to the description of enzymic reactions. The basic assumption of this formalism is that the net flux through a reaction is related to the free energy change, a relationship which is usually assumed to be linear. These assumptions are shown to be approximately true for the trivial case of an enzyme reaction within 0.8 kJ/mol (0.2 kcal/mol) of equilibrium in the absence of changes in any regulatory parameters (such as inhibitor, activator, or enzyme concentration). For all other reaction conditions the net flux is not related to the free energy change and in special cases for which an apparent relationship is seen, it is not linear. Thus, application of the formalism of irreversible thermodynamics gives rise to qualitatively and quantitatively erroneous results and conclusions. Since most regulatory enzymic reactions are far from equilibrium, and the net reaction rate of such reactions is regulated by changes in inhibitors, activators and/or enzyme concentration, the formalism of irreversible thermodynamics is in general neither applicable nor useful in understanding the behavior of biological reaction systems.
已经对称为不可逆热力学的形式体系在描述酶促反应方面的适用性进行了研究。该形式体系的基本假设是，通过反应的净通量与自由能变化相关，这种关系通常被假定为线性的。对于在没有任何调节参数（如抑制剂、激活剂或酶浓度）变化的情况下，处于平衡状态0.8 kJ/mol（0.2 kcal/mol）范围内的酶促反应的简单情况，这些假设被证明大致是正确的。对于所有其他反应条件，净通量与自由能变化无关，并且在特殊情况下，尽管可以看到一种表观关系，但它不是线性的。因此，应用不可逆热力学的形式体系会产生定性和定量上错误的结果和结论。由于大多数调节性酶促反应远离平衡，并且此类反应的净反应速率受抑制剂、激活剂和/或酶浓度变化的调节，所以不可逆热力学的形式体系通常既不适用于也无助于理解生物反应系统的行为。
